docs: def wrap_viscm(cmap, dpi=100, saveplot=False):
      '''Evaluate goodness of colormap using perceptual deltas.
  
      :param cmap: Colormap instance.
      :param dpi=100: dpi for saved image.
      :param saveplot=False: Whether to save the plot or not.
  
      '''
  
      from viscm import viscm
  
      viscm(cmap)
      fig = plt.gcf()
      fig.set_size_inches(22, 10)
      plt.show()
  
      if saveplot:
          fig.savefig('figures/eval_' + cmap.name + '.png', bbox_inches='tight', dpi=dpi)
          fig.savefig('figures/eval_' + cmap.name + '.pdf', bbox_inches='tight', dpi=dpi)